Problem: $ { {4} \times \left[\begin{array}{rr}{-1} & {3} \\ {3} & {0} \\ {-2} & {-2}\end{array}\right] = {?} } $
Explanation: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{4}\times{-1} & {4}\times{3} \\ {4}\times{3} & {4}\times{0} \\ {4}\times{-2} & {4}\times{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{-4} & {12} \\ {12} & {0} \\ {-8} & {-8}\end{array}\right]}$